/// <summary>
/// Determines whether the <see cref="ILicense.Signature"/> property verifies for the specified key.
/// </summary>
/// <param name="publicKey">The public key in xml string format to verify the <see cref="ILicense.Signature"/>.</param>
/// <returns>true if the <see cref="ILicense.Signature"/> verifies; otherwise false.</returns>
public bool VerifySignature(string publicKey)
{
var signTag = Element("Signature");
if (signTag == null)
return false;
try
{
signTag.Remove();
using (var e = new Security.Cryptography.ElGamal.ElGamalManaged())
{
e.FromXmlString(publicKey);
return e.VerifySignature(Encoding.UTF8.GetBytes(ToString(SaveOptions.DisableFormatting)),
Convert.FromBase64String(signTag.Value));
}
}
finally
{
Add(signTag);
}
}
/// <summary>
/// Compute a signature and sign this <see cref="ILicense"/> with the provided key.
/// </summary>
/// <param name="privateKey">The private key in xml string format to compute the signature.</param>
public void Sign(string privateKey)
{
var signTag = Element("Signature") ?? new XElement("Signature");
try
{
if (signTag.Parent != null)
signTag.Remove();
using (var e = new Security.Cryptography.ElGamal.ElGamalManaged())
{
e.FromXmlString(privateKey);
var signature = e.Sign(Encoding.UTF8.GetBytes(ToString(SaveOptions.DisableFormatting)));
signTag.Value = Convert.ToBase64String(signature);
}
}
finally
{
Add(signTag);
}
}
